Owners of a Southeast Portland home will participate in an international green building open house this weekend.

The International Passive House Association is sponsoring open houses across the world, Friday through Sunday, to raise awareness about the Passive House standard, which originated in Germany. The standard is still most popular in Europe, and most homeowners participating in the open house are overseas; however, a handful of American homeowners also will be part of the event’s 20th anniversary.

“The anniversary is an important milestone,” said Tad Everhart, who has worked for two years to retrofit his home to the Passive House standard for existing buildings. “It just felt like the right thing to take part in it. It’s a wonderful notion to have people open their houses so members of the public can see what is possible.”

Tad and Maria Everhart are now two months away from finally achieving the certification, which has cost approximately $140,000 so far – not including the months of uncompensated labor performed by Tad and his brother.

Passive House techniques produce a super-insulated, yet well-ventilated home, and Everhart said he has learned several lessons that would help him cut costs and work more efficiently if he was to take on another Passive House project.

The Everharts’ house features Larsen trusses, which were built on-site. But Tad Everhart said the premade trusses can now be purchased in Europe and delivered to the project site, which would help reduce labor time.

The house also includes many imported materials, including a new Zehnder America “ComfoAir 350” heat recovery ventilator from the Netherlands. Quadruple-glazed SeriousWindows, triple-glazed Innotech doors and a variety of innovative insulations also were installed.